Various rotary axial valves are known in the art. One example is the “Thayer Valve” which is the subject of U.S. Pat. No. 4,469,002, filed in May 1982, issued in September 1984, and is now expired.
Rotary axial valves generally include housing and a rotor having at least two apertures extending through the rotor and the housing. At least one of the passages is substantially straight, while the other deflects the flow of air at an angle.
The apertures and passages are configured to align axially with the instrument's lead pipe, main bore, and slide loop ends to allow the user to better control airflow through these components and reduce the effort required to achieve a range of notes and tones.
A problem known in the art with traditional axial flow valves is that they are prone to wear because of the continuous friction between the rotor, housing and back plate.
Friction between these components will eventually compromise the seal of the valve necessary to direct airflow through the desired passages to achieve optimum tone quality.
Friction and the loss of seal within a valve result in costly repairs and replacements and compromised sound quality.